First paragraph: In this first paragraph you need mention the exact reasons for writing the business letter. This paragraph will also mention the details from where you come to know about availability of the business opportunities.

Second paragraph: In this paragraph you need to give details about you or your company like achievements and experience. This gives you an opportunity to present yourself or your company as an ideal option to do business with the recipient.

Third paragraph: in this paragraph you need to conclude by expressing that how honorable it will be for you to do business with the recipient and also show your gratitude.